Typewriter keyboard



Feb. 25, 1941. A R pomo-r .2,232,684

EEEEEEEEEEEEEEEEEEE INVENTOR.

GA? Pobrez- By/(Q ATTORNEYS.

Patented Feb. z5, 1941 rar-ENT erica TYPEWVRITER KEYBOARD Gaston Raimundo Poirot, villa smitheela,

l Argentina Application September 15, 1939, Serial No. 295,144 In Argentina August 8, 1939 y3 claims.

The present invention relates to typewriters and particularly to the keyboards thereof.

As is well known, the vast majority of typewriters are provided with a keyboard which has been standardised at least so far as the arrangement and distribution of the numeral and alphabetical character key-s are concerned, although for certain languages as also for special purposes, additional character keys may be provided. Such additional character keys have, however, borne extra characters not comprised in the standard keyboard.

` Neglecting such 4special additional character keys, the standard keys are arranged so as to provide two equal groups of four rows of five character keys each, this arrangement being intended to facilitate typing by the generally adopted ten finger touch method. The spacebar, which is common to all typewriters'is arranged to be operated by the thumbsof two hands, the thumb used depending onthe manner in which the word preceding thespaceends.

Ithas been found, as will hereinafter beI shown, thatvthe standard keyboard gives av speed eiciency of only approximately 66% which implies that about a third of the time taken by a typist operating such a keyboard is Wasted.

The object of the present invention is to remedy this defect of the standard keyboard and to provide an improved keyboard whereby a considerable increase in speed efficiency may be obtained.

A further object of the present invention is to provide an improved keyboard'for typewriters, which shall be readily embodiable without requiring complete redesign of the machine base castings, such as would prevent the use of at least some of the standardised models of machine bases, and frames in the performance of the invention, and which shall have a speed efficiency of 90% or more.

In essence the invention consists in providing in a typewriter of the kind having a keyboard comprising a plurality of different character keys grouped to form a group of character keys intended to be operated by one hand and a second group of diiferent character keys intended to be operated by the other hand anddisposed alongside the first-mentioned group, in each group a plurality of additional character keys eachof which duplicates a selected character key of the other group.

The invention will now be further explained with reference to the accompanying drawing, in which the single gure is a diagrammatic illustration of a preferred character key arrangement according to the present invention.

The conventional keyboard of a modern typewriter is composed of a plurality of character keys each relating to a different character, said keys being arranged in two groups, of which one group, is intended to be operated by the fingers of the left hand, `while the other groupvis intended to be operated by the fingers of the right hand in a system of ten nger touch typing. The keyboard includes likewise the space-bar intended to be operated by the thumbs of the two hands.

Only one key. is present for every character included in the board and the keys are arranged not in alphabetical order, but in accordancewith a distribution system which is based, as is well known, on the average frequency of occurrence of the individual characters in the matter to be typed. With respectto the lalphabetical portion of the keyboard, the arrangement has been found satisfactory in practice for Athe majority of modern languages, but obviously special keys `will be provided where necessary to take care of any special characters or signs, such as accents, paragraph or'compoun'd consonants, which may be 9 peculiar to a givenlanguage, or required or helpful for a specic'purpose. The following discussion is not concerned with such extra keys since the present invention is primarily intended to be applied for improving the speed efficiency of the part of the keyboard common to all modern standardised machines, although it is to be understood that the invention may with advantage be applied to the more specialised machines as well.

vFor the purpose of examining the speed efiiciency of the standard keyboard, it is convenient to take a passage comprising one hundred operations, that is to say, one hundred key or spacebar depressions, as for example the passage:

as explained in these statements, the proposals do not involve any fundamental change in the scheme If such a passage is analysed on the basis of the ten finger touch method of typing, it'willbe found that the work of the lingers, thumbs and hands is distributed as follows:

Strokes 36 letters and spaces are alternate strokes, i. e. they are struck alternately by one hand and then bythe other 36 44 letters and spaces are 22 sets of 2 strokes produced by one hand- 44 15 strokes are 5 sets of 3 strokes produced by one hand 15 strokes are one set typed by the same hand 5 Total 100 These results will be clear from the following table:

Table I as l ts 2 t i 1 blank 1 l in 3 with-space ex 2 t 2 with space v l pl 2 h 1 ol 2 a l e 1 ve 2 in 2 p 2 with space blank 1 ed 2 r 1 a 1 in 3 with space opo 3 ny 2 t 2 with space sa 2 f 2 with space h 1 1 1 un 2 ese 3 s 1 da 2 space l blank 1 m 1 state 5 d 1 e l m 1 o 1 n 1 e 1 blank l ta 2 n A 1 no 2 1 1 Strokes 36 singles, or 36 22 doubles, or 44 5 triples or 15 l quintuple, or 5 Total `100 It will now readily be seen that every time a set of strokes is typed by the same hand, the other hand is idle, but that this hand would be doing half the work were the arrangement of the keys to allow it. It would strike one a'lternate stroke between two strokes of the hand that is Working.

In the word was for instance, which is written entirely with the left hand, the right hand could strike the a if there were an a on the right hand side, which, together with the bar also struck by the right thumb at the end of the word, would simply increase the speed by 50%, or would enable one to do double work.

That the speed is so increased is seen from the tact .that a line of the word of, which is well balanced Ibetween the two hands, will be written in half the time it will take to type the letters ed written by the left hand, i. e. a line of ofofofofofofof, etc. Ito Ithe end of the line, shows a 50% increase in speed over a line of ededededededed etc.

Therefore, when making sets of strokes, the speed is only half of what it would be if t-he strokes were divided alternately between the two hands.

Hence as a basis for calculation, each alternate stroke is taken as equal to one point, and each stroke from a set of strokes (spaces included) is taken as equivalent to half a point.

On this basis the example analysed in Table I gives the results shown in Table II.

Table II 36 letters or spaces are 36 alternate movements, and represent 36 44 letters or spaces are 22 groups of 2 strokes, and represent. .22

In order to arrive at a fair average of the speed eiiiciency of the standard keyboard, a number of passages of 100 letters and blanks were analyzed in the same way as the example given above, the result being an average efficiency of 70% and an average loss of time of 30%.

As will be seen from the foregoing, some of the characters of each group form sets which are of fairly frequent recurrence in any particular language, but because they form what may be termed one-handed sets, that is, sets the keys of which are struck by one h-and only, it is precisely these characters which contribute most to the observed ineiciency. Ideally, if every character in the keyboard were duplicated, the basis of calwith space 2 1 1 1 2 3 with space S12 with space 1 1 2 l 1 1 1 l Left hand: .,hulionmp Right hand: earstfcdvw will give an average speed efficiency in English of about 98% as against 70% for the present keyboard.

Now, this 98% speed efficiency in the keyboard represents a speed increase of as shown by the following calculation.

Taking a speed with the present keyboard of words a minute, at speed efficiency, an efficiency of 98% should give:

60 98 70 words a minute, instead of 60, or a 40% increase.

Calculations with 50 or '70 words a minute will It will be seen that the addition of the character keys indicated above, permits of a nearly perfect alternation of key operation. It should,

percent of the total. percent of the total.

l5 letters or spaces are 5 groups of 3 strokes, and represenL-. 7. 50 percent of the total. 5 letters or spaces are 1 group of 5 strokes, and represent 2. 50 percent ofvthe total.

Total 100 letters or spaces, representing a value of Therefore, the keyboard in this case has a speed eiciency of 68%, and the time wasted is 32%. y

however, be borne in mind that the characters selected for duplication in order to give a similar increase Vin efficiency will `depend to a considerable extent on the language or purpose for which a particular inodel of typewriter is designed. The selection given above has been found suitable for English, German, French and Spanish.

The drawing shows a preferred arrangement of the duplicated letters, and it Will be noted that the improved keyboard consists as in the case of the standard type, of a plurality of different character keys I0, disposed in a left-hand group 12a and a right-hand group Illa and that in ea'ch group a number of duplicate keys I8, 20 have been added. The .characters M, U, L, O, I, N, P, H, point and comma of the right-hand group 14a have been duplicated on the left-hand group l2a, and the characters E, A, R, S, T, C, D, F, V, W, as well as the 2 and 3 of the left-hand group have been duplicated in the right-hand group I4a. For clearness, the duplicated character-'keys have been shown in heavier lines. It will be noted that the additional characters do not interfere with the arrangement of the characters forming the normal keyboard, except for the fact that the line of numenals is separated from the alphabetical blocks by a line of duplicated characters. Thus the improved keyboard may be used by persons who are unaccustomed to the use of the duplicate keys, and such a typist need only remember that a whole line of characters must be skipped in order to reach the numerals.

It will be observed that in the drawing, the numerals 2 and 3 have been duplicated in the righthand group, although these characters are not given in the above-mentioned selection. This will exemplify the variations which may be made in the selection of the characters to be duplicated. These two keys as well as the point and comma keys of the left-hand group may be utilized for duplicating an additional single-case character such, for example, as an asterisk or an inverted exclamation mark, such additional character being located in the higher case position on the type bar.

I claim:

1. In a typewriter, wherein all of the type bars print from a single position, and a platen is provided for moving succeeding portions of paper to be printed, a group of character keys intended to be operated by one hand, and a second group of character keys intended to be operated by the other hand, each of said groups including a block of alphabetical keys, said blocks being arranged contiguously to form a complete alphabetical section, each group further including a plurality of non-alphabetical keys and a plurality of extra character keys duplicating selected character keys of the other group; said extra character keys being disposed outside of said complete alphabetical section, whereby the contiguity of said blocks is maintained.

2. In a typewriter, wherein all of the type bars print from a single position, and a platen is provided for moving succeeding portions of paper to be printed, a group of character keys intended to be operated by one hand, and a second group of character keys A'intended to be'operated by the other hand', each group including a block of alphabetical keys, said blocks being arranged contiguously to form a complete alphabetical section, each group further including a plurality of special keys including numerical keys arranged above said alphabetical s'ection and a plurality of extra character keys duplicating selected character keys of the other group; said extra character keys being disposed outside of said complete alphabetical section and between said section and said numerical keys.

3. In a typewriter, wherein all of the type bars print from a single position, and a platen is provided for moving succeeding portions of paper to be printed, a group of character keys intended to be operated by one hand, and a second group of character keys intended to be operated by the other hand, each group including a block of alphabetical keys, said blocks being arranged contiguously alongside each other to form a complete alphabetical section, each group further including a plurality of special character keys arranged laterally of said section, a plurality of numerical keys arranged above said section, and a plurality of extra character keys duplicating selected character keys of the other group; said extra character keys being disposed between said alphabetical section and said numerical keys and interspersed among the laterally arranged special keys.

GASTON RAIMUNDO POIROT. 

